Boiling bed coal tar hydrotreating-hydrocracking composite catalyst and preparation method thereof

Abstract

The invention relates to a boiling bed coal tar hydrotreating-hydrocracking composite catalyst and a preparation method thereof. The boiling bed coal tar hydrotreating-hydrocracking composite catalystis prepared from the following components in percentage by mass: MoO3, WO3, NiO, aluminum oxide, silicon oxide molecular sieve and assistant. An acidized silicon-containing raw material and alkali gas react with each other, and the reaction product is cured to generate microsphere gel which has higher scale-accommodating capability and proper cracking performance. Active metal nickel, the assistant and a carrier raw material are prepared into slurry, the NiO is highly dispersed on the catalyst carrier, and nickel aluminum spinel is formed by a small amount of nickel and aluminum, so that thewater resistance and friction resistance of the catalyst are enhanced. Spray drying is performed, so that the grain distribution is concentrated, and high mechanical strength and abrasion resistance are achieved. A curing agent is added into the slurry, and the channel of the catalyst is enlarged in the escaping process of ammonia gas released in a drying process, so that the channel distributionis concentrated, and larger pore volume, larger specific surface area and higher abrasion resistance are achieved. The boiling bed coal tar hydrotreating-hydrocracking composite catalyst has higher hydrogenation activity, proper cracking activity and higher stability. The preparation method is simple and is low in cost.

Description

technical field [0001] The invention relates to a petrochemical catalyst, which is a fluidized bed coal tar hydrotreating-hydrocracking composite catalyst and a preparation method thereof. Background technique [0002] Coal tar is an important by-product of coal pyrolysis and carbonization process. It is a complex mixture of various substances. According to the temperature and process method of coal pyrolysis and carbonization, coal tar can be divided into low-temperature coal tar and high-temperature coal tar. [0003] Compared with petroleum heavy fractions, coal tar raw materials have the characteristics of high content of heteroatoms such as sulfur and nitrogen, high ash content, high content of polycyclic aromatic hydrocarbons, and high content of colloids and asphaltenes. Therefore, direct combustion will produce a large amount of sulfide and nitride, causing serious environmental pollution. Clean processing and effective utilization of coal tar become more important....

AI Technical Summary

Problems solved by technology

The fixed bed hydrogenation process has the following problems in the treatment of coal tar: (1) Due to the heavy coal tar, the catalytic reaction conditions are relatively harsh, and the high-nitrogen raw material will accelerate the deactivation of the catalyst. The service life of the catalyst is very short, and the product properties cannot be guaranteed (2) Due to the high mechanical impurities of coal tar and the high pressure drop of the catalyst bed, in order to meet the product index, the fixed bed reactor system needs to adopt a protective reactor or a switchable reactor, thereby increasing the investment cost

[0007] CN101085935 discloses a coal liquefied oil fluidized bed hydrogenation catalyst carrier and its preparation method, and CN101085934 discloses a coal liquefied oil fluidized bed hydrogenation catalyst and its preparation method. The two patents are to improve the mechanical strength and wear resistance of the catalyst. In the carrier preparation process, alumina fibers with a content of 3wt% to 10wt% are added. Since the pore volume of the alumina fibers is 0.01 to 0.20ml / g, the pore volume of the final catalyst is small, which affects the scale capacity of the catalyst. In addition, the diameter of the catalyst carrier is a thin strip or spherical shape of 0.8-1.2 mm, which increases the path for the raw material to diffuse into the catalyst and also affects the activity of the catalyst.

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